Galectin-3 detection on large-needle aspiration biopsy improves preoperative selection of thyroid nodules: a prospective cohort study

Diagnostic Accuracy of Fine-Needle Biopsy in the Detection of Thyroid Malignancy: A Systematic Review and Meta-analysis

Importance

Fine-needle biopsy (FNB) became a critical part of thyroid nodule evaluation in the 1970s. It is not clear how diagnostic accuracy of FNB has changed over time.

Objective

To conduct a systematic review and meta-analysis estimating the accuracy of thyroid FNB for diagnosis of malignancy in adults with a newly diagnosed thyroid nodule and to characterize changes in accuracy over time.

Data Sources

PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials were searched from 1975 to 2020 using search terms related to FNB accuracy in the thyroid.

Study Selection

English-language reports of cohort studies or randomized trials of adult patients undergoing thyroid FNB with sample size of 20 or greater and using a reference standard of surgical histopathology or clinical follow-up were included. Articles that examined only patients with known thyroid disease or focused on accuracy of novel adjuncts, such as molecular tests, were excluded. Two investigators screened each article and resolved conflicts by consensus. A total of 36 of 1023 studies met selection criteria.

Data Extraction and Synthesis

The MOOSE guidelines were used for data abstraction and assessing data quality and validity. Two investigators abstracted data using a standard form. Studies were grouped into epochs by median data collection year (1975 to 1990, 1990 to 2000, 2000 to 2010, and 2010 to 2020). Data were pooled using a bivariate mixed-effects model.

Main Outcomes and Measures

The primary outcome was accuracy of FNB for diagnosis of malignancy. Accuracy was hypothesized to increase in later time periods, a hypothesis formulated prior to data collection.

Results

Of 16 597 included patients, 12 974 (79.2%) were female, and the mean (SD) age was 47.3 (12.9) years. The sensitivity of FNB was 85.6% (95% CI, 79.9-89.5), the specificity was 71.4% (95% CI, 61.1-79.8), the positive likelihood ratio was 3.0 (95% CI, 2.3-4.1), and the negative likelihood ratio was 0.2 (95% CI, 0.2-0.3). The area under the receiver operating characteristic curve was 86.1%. Epoch was not significantly associated with accuracy. None of the available covariates could explain observed heterogeneity.

Conclusions and Relevance

Accuracy of thyroid FNB has not significantly changed over time. Important developments in technique, preparation, and interpretation may have occurred too heterogeneously to capture a consistent uptrend over time. FNB remains a reliable test for thyroid cancer diagnosis.

Systematic Review and Meta-Analysis to Identify the Immunocytochemical Markers Effective in Delineating Benign from Malignant Thyroid Lesions in FNAC Samples

Conventional cytology-based diagnosis for thyroid cancer is limited with more than 30-45% of nodules categorized as indeterminate, necessitating surgery for confirming or refuting the diagnosis. This systematic review and meta-analysis were aimed at identifying immunocytochemical markers effective in delineating benign from malignant thyroid lesions in fine needle aspiration cytology (FNAC) samples, thereby improving the accuracy of cytology diagnosis. A systematic review of relevant articles (2000-2021) from online databases was carried out and the search protocol registered in PROSPERO database (CRD42021229121). The quality of studies was assessed using QUADAS-2. Review Manager 5.4.1 from Cochrane collaboration and MetaDisc Version 1.4 was used to conduct the meta-analysis. Bias in the studies were visually analyzed using funnel plots, and statistical significance was evaluated by Egger's test. Systematic review identified 64 original articles, while meta-analysis in eligible articles (n = 41) identified a panel of 5 markers, Galectin-3, HBME-1, CK-19, CD-56, and TPO. Assessment of the diagnostic performance revealed that Gal-3 (sensitivity: 0.81; CI: 0.79-0.83; specificity: 0.84; CI: 0.82-0.85) and HBME-1 (sensitivity: 0.83; Cl: 0.81-0.86; specificity: 0.85; CI: 0.83-0.86) showed high accuracy in delineating benign from malignant thyroid nodules. Efficacy analysis in indeterminate nodules showed Gal-3 and HBME-1 have high specificity of 0.86 (CI 0.84-0.89) and 0.82 (CI 0.78-0.86), respectively, and low sensitivity of 0.76 (CI 0.72-0.80) and 0.75 (CI 0.70-0.80), respectively. Diagnostic odds ratio (DOR) of Galectin-3 and HBME-1 were 39.18 (CI 23.38-65.65) and 24.44 (CI 11.16-53.54), respectively. Significant publication bias was observed for the markers Galectin-3 and CK-19 (p < 0.05). The panel of 5 markers identified from this meta-analysis are high-confidence candidates that need to be validated in thyroid cytology to establish their efficacy and enable clinical applicability.

Quantitative Analysis of Galectin-3 Expression in Benign and Malignant Thyroid Nodules

In this study, galectin-3 was analyzed as a potential marker for preoperative detection of malignant thyroid lesions. Galectin-3 expression was analyzed by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) in preoperative thyroid fine-needle aspirates from 245 patients with thyroid nodules. Out of 245 samples, 238 were adequate for analysis by RT-PCR. Galectin-3 was positive in 34 (89.5%) of 38 papillary carcinomas, 3 (89.5%) of 4 follicular carcinomas, 17 (53.1%) of 32 follicular adenomas, 2 (33.3%) of 6 Hurthle cell adenoma, 11 (28.2%) of 39 Hashimoto thyroiditis, and 69 (57.9%) of 119 nodular goiter samples. Galectin-3 showed specificity of 49.5%, sensitivity of 88.1%, positive predictive value of 27.2%, and negative predictive value of 95.1% as a marker for detection of malignant thyroid nodules. Owing to the relatively low positive predictive value due to the relatively high false positive rate, the clinical value of galectin-3 analyzed by quantitative real-time RT-PCR as a marker for preoperative detection of malignant thyroid lesions is limited.

Galectin-3: The Impact on the Clinical Management of Patients with Thyroid Nodules and Future Perspectives

Galectins (S-type lectins) are an evolutionarily-conserved family of lectin molecules, which can be expressed intracellularly and in the extracellular matrix, as well. Galectins bind β-galactose-containing glycoconjugates and are functionally active in converting glycan-related information into cell biological programs. Altered glycosylation notably occurring in cancer cells and expression of specific galectins provide, indeed, a fashionable mechanism of molecular interactions able to regulate several tumor relevant functions, among which are cell adhesion and migration, cell differentiation, gene transcription and RNA splicing, cell cycle and apoptosis. Furthermore, several galectin molecules also play a role in regulating the immune response. These functions are strongly dependent on the cell context, in which specific galectins and related glyco-ligands are expressed. Thyroid cancer likely represents the paradigmatic tumor model in which experimental studies on galectins' glycobiology, in particular on galectin-3 expression and function, contributed greatly to the improvement of cancer diagnosis. The discovery of a restricted expression of galectin-3 in well-differentiated thyroid carcinomas (WDTC), compared to normal and benign thyroid conditions, contributed also to promoting preclinical studies aimed at exploring new strategies for imaging thyroid cancer in vivo based on galectin-3 immuno-targeting. Results derived from these recent experimental studies promise a further improvement of both thyroid cancer diagnosis and therapy in the near future. In this review, the biological role of galectin-3 expression in thyroid cancer, the validation and translation to a clinical setting of a galectin-3 test method for the preoperative characterization of thyroid nodules and a galectin-3-based immuno-positron emission tomography (immuno-PET) imaging of thyroid cancer in vivo are presented and discussed.

Galectins and Carcinogenesis: Their Role in Head and Neck Carcinomas and Thyroid Carcinomas

Head and neck cancers are among the most frequently occurring cancers worldwide. Of the molecular drivers described for these tumors, galectins play an important role via their interaction with several intracellular pathways. In this review, we will detail and discuss this role with specific reference to galectins-1, -3, and -7 in angiogenesis, cell proliferation, and invasion as well as in cell transformation and cancer progression. Furthermore, we will evaluate the prognostic value of galectin expression in head and neck cancers including those with oral cavity, salivary gland, and nasopharyngeal pathologies. In addition, we will discuss the involvement of these galectins in thyroid cancers where their altered expression is proposed as a new diagnostic biomarker.

Galectin-3 Performance in Histologic a Cytologic Assessment of Thyroid Nodules: A Systematic Review and Meta-Analysis

The literature on Galectin-3 (Gal-3) was systematically reviewed to achieve more robust information on its histologic reliability in identifying thyroid cancers and on the concordance between Gal-3 test in histologic and cytologic samples. A computer search of the PubMed and Scopus databases was conducted by combinations of the terms thyroid and Gal-3. Initially, 545 articles were found and, after their critical review, 52 original papers were finally included. They reported 8172 nodules with histologic evaluation of Gal-3, of which 358 with also preoperative FNAC Gal-3 assessment. At histology, Gal-3 sensitivity was 87% (95% confidence intervals [CI] from 86% to 88%), and specificity 87% (95% CI from 86% to 88%); in both cases, we found heterogeneity (I₂ 85% and 93%, respectively) and significant publication bias (p < 0.001). The pooled rate of positive Gal-3 at fine needle aspiration (FNAC) among cancers with histologically proven Gal-3 positivity was 94% (95% CI from 89% to 97%), with neither heterogeneity (I₂ 14.5%) nor bias (p = 0.086). These data show high reliability of Gal-3 for thyroid cancer at histology, while its sensitivity on FNAC samples is lower. The limits of cytologic preparations and interpretation of Gal-3 results have to be solved.

Combination of galectin-3, CK19 and HBME-1 immunostaining improves the diagnosis of thyroid cancer

Currently, fine-needle aspiration is the most frequently used pre-operative technique for diagnosis of malignant thyroid tumors, however, pathologists are unable to reach efficient and accurate differential diagnoses between benign and malignant thyroid nodules. To aid in resolving this issue, immunohistochemistry for galectins (gal)-1, −3, −7, −8, cytokeratin 19 (CK19), Hector Battifora Mesothelial Epitope-1 (HBME-1) and thyroid peroxidase (TPO) was performed on two tissue microarrays composed of 66 follicular adenomas (FA) and 66 papillary carcinomas (PC). The identification of optimal cut-off levels and the diagnostic value of single immunomarkers or combinations were evaluated using the receiver operating characteristic curve analysis. Signal intensities for gal-1, gal-3, CK19 and HBME-1 were significantly greater in PC compared with FA (P<0.001). Conversely, expression levels of TPO were significantly increased in FA compared with PC (P<0.001). Gal-3 and CK19 appeared to be the most sensitive markers (97 and 98%, respectively), whereas galectin-1 was the most specific (97%). The combination of gal-3, CK19 and HBME-1 acted as the most efficient and informative marker panel reaching the greatest specificity (97%) and sensitivity (95%) for the diagnosis of PCs. The findings suggest that this combination of markers may improve the reliability of diagnosis of thyroid cancer.

Galectin-1 is a diagnostic marker involved in thyroid cancer progression

Fine-needle aspiration (FNA) is the most commonly used pre-operative technique for diagnosis of malignant thyroid tumor. However, many benign lesions, with indeterminate diagnosis following FNA, are referred to surgery. Based on multifunctionality of the endogenous galectin-1, we aimed to assess its status for early diagnosis of thyroid cancer. Immunohistochemistry for galectin-1 and -3 was performed on a clinical series of 69 cases of thyroid lesions. Galectin-1 expression was further examined in two additional tissue microarrays (TMA) composed of 66 follicular adenomas and 66 papillary carcinomas in comparison to galectin-3 and cytokeratin-19 (CK19). In addition, a knockdown of galectin-1 in papillary (TPC-1) and anaplastic (8505C) thyroid cancer cell lines was achieved by lentiviral transduction for in vitro experiments. A murine orthotopic thyroid cancer model was used to investigate tumor growth and metastatic ability. Immunohistochemical analyses of galectin-1 and -3 in the series of 69 cases of thyroid lesions revealed that galectin-1 was completely absent in the epithelial compartment of all benign thyroid lesions. Levels of both galectins significantly increased in the cytoplasmic compartment of malignant thyroid cells. Galectin-1 expression in the TMA yielded an excellent specificity (97%), while galectin-3 and CK19 presented a higher sensitivity (>97%) in discriminating benign from malignant thyroid lesions. In vitro experiments revealed that migration was negatively affected in TPC-1 galectin-1 knockdown (KD) cells, and that proliferation and invasion capacity of 8505C cells decreased after galectin-1 KD. Moreover, an orthotopic mouse model displayed a lower rate of tumor development with galectin-1 KD thyroid anaplastic cancer cells than in the control. Our findings support the introduction of galectin-1 as a reliable diagnostic marker for thyroid carcinomas. Its involvement in cell proliferation, migration, invasion and tumor growth also intimate functional involvement of galectin-1 in the progression of thyroid carcinoma, suggesting its potential as a therapeutic target.

Diagnostic biomarkers of differentiated thyroid cancer

The incidence of thyroid cancer has been increasing all around the world in the past decades. Early detection is one of the keys to reduce the mortality. Currently, fine-needle aspiration (FNA) guides the management of patients with a thyroid nodule. The use of FNA can reduce unnecessary thyroid surgery by twenty-five percent. However, the prevalence of non-diagnostic and indeterminate cytology from FNA is still high, approximately thirty percent. Many biomarkers were developed to differentiate between the benign and malignant thyroid nodule. This review summarizes each diagnostic biomarker of differentiated thyroid cancer. Sensitivity, specificity, and positive and negative predictive values of individual cytological laboratory need to be considered before implementation of each biomarker. Moreover, follow-up is still mandatory in negative biomarker tests because all genomic and proteomic alterations in thyroid cancer are still unknown.

Thyroid cancer in children and adolescents

PURPOSE OF REVIEW

Paediatric thyroid cancer is a rare disease, but its incidence is rising in recent reports. This review aims at integrating recent findings into the current optimal diagnostic and therapeutic approach.

RECENT FINDINGS

The causal relationship of differentiated thyroid cancer (DTC) to radiation exposure is increasingly unravelled. Research progressively uncovers the genetic basis, such as RET (rearranged during transfection)/papillary thyroid cancer (PTC) rearrangement and RET-mutations. Knowledge of oncogenic signalling pathways nowadays starts to help finetuning diagnosis, prognosis and treatment. This knowledge complements the current state-of-the-art of paediatric thyroid cancer treatment. In childhood, DTC presents at a more advanced stage and implies higher recurrence rates, recurrences often occurring decades later. Treatment should minimize not only these recurrences but also long-term treatment sequelae. Total thyroidectomy and central compartment dissection by a high-volume surgeon and radioactive iodine is the preferred approach for most children with DTC. For children with medullary thyroid cancer within the MEN2 framework, when possible, prophylactic thyroidectomy is performed. Unfortunately, frequently, the diagnosis is still made at a later stage, and then requires total thyroidectomy with dissection of the central compartment and the lateral neck, when involved.

SUMMARY

The management complexity, the essential long-term follow-up and the lifetime burden of eventual complications demands management of paediatric thyroid cancer by physicians with the highest expertise. In such hands, excellent results can be obtained.

Does large needle aspiration biopsy add pain to the thyroid nodule evaluation?

Thyroid large needle aspiration biopsy is disregarded because it is thought to be associated with pain. This is in contrast with our 32 years long experience. We surveyed reports of pain in patients examined with fine needle aspiration biopsy (78, 87.2% women, mean age 59 years) or FNAB+large needle aspiration biopsy (48, 87.5% women, mean age 60 years). Each patient was questioned regarding a) no unpleasant sensation (score "0"); b) unpleasant sensation ("1"); c) mild pain (no analgesic used; "2"); or d) pain (analgesic used; "3"). The mean size of the needle used was for FNAB 22.3±0.7 or 20.8±1 gauge in the fine needle aspiration or fine needle aspiration plus large needle aspiration biopsy group, respectively (p<.0001). The number of percutaneous punctures was higher in the fine needle aspiration plus large needle aspiration biopsy group. However, the pain score in the fine needle aspiration biopsy or fine needle aspiration biopsy plus large needle aspiration biopsy group was not significantly different. Large needle aspiration biopsy after fine needle aspiration biopsy does not add any discomfort or pain and therefore in light of the demonstrable benefits, should be included in clinical algorithms for the evaluation of thyroid nodules.

Are risk factors common to thyroid cancer and nodule? A forty years observational time-trend study

A progressive increase in the incidence of thyroid cancer (TC) has been reported over the last few decades. This either reflects the increased number of newly discovered and accurately selected thyroid nodules with more sensitive technologies and a relative more potent carcinogenic effect of pathogenetic factors in malignant, but not benign nodules. This observational time-trend study addresses this issue by analysing the proportion of TC within 8411 consecutive thyroid nodule (TN) patients evaluated in Pisa by the same pathology Department and individual clinician over a four-decade period. From 1972 to 1979 surgery was used to detect TC among the TN patients: 1140 TN patients were operated on and 35 cancers were detected (3.1% of all the TN patients). Subsequently, needle aspiration techniques were used to select TN for surgery. From 1980 to 1992, 5403 TN patients were examined, 483 were selected for surgery, and 150 cancers were found (2.8% of all the TN patients). From 1993 to 2010, 1568 TN patients were examined, 143 were selected for surgery, and 46 cancers were found (2.9% of all the TN patients). Therefore, in the University Hospital of Pisa, and independent of preoperative TN selection protocols, these proportions of TN eventually found to harbor TC remained statistically unchanged over 40 years (p = 0.810). This finding suggests that pathogenic risk factors and more sensitive diagnostic technologies did not differentially affect the incidence of TN and TC.

Proteomic analysis of differentially expressed proteins in normal human thyroid cells transfected with PPFP

The fusion gene encoding the thyroid-specific transcription factor PAX8 and peroxisome proliferator-activated receptor γ (PPARγ (PPARG)) (designated as the PPFP gene) is oncogenic and implicated in the development of follicular thyroid carcinoma (FTC). The effects of PPFP transfection on the biological characteristics of Nthy-ori 3-1 cells were studied by MTT assay, colony formation, soft-agar colony formation, and scratch wound-healing assays as well as by flow cytometry. Furthermore, the differentially expressed proteins were analyzed on 2-DE maps and identified by MALDI-TOF-MS. Validation of five identified proteins (prohibitin, galectin-1, cytokeratin 8 (CK8), CK19, and HSP27) was determined by western blot analysis. PPFP not only significantly increased the viability, proliferation, and mobility of the Nthy-ori 3-1 cells but also markedly inhibited cellular apoptosis. Twenty-eight differentially expressed proteins were identified, among which 19 proteins were upregulated and nine proteins were downregulated in Nthy-ori 3-1(PPFP) (Nthy-ori 3-1 cells transfected with PPFP). The western blot results, which were consistent with the proteome analysis results, showed that prohibitin was downregulated, whereas galectin-1, CK8, CK19, and HSP27 were upregulated in Nthy-ori 3-1(PPFP). Our results suggest that PPFP plays an important role in malignant thyroid transformation. Proteomic analysis of the differentially expressed proteins in PPFP-transfected cells provides important information for further study of the carcinogenic mechanism of PPFP in FTCs.

Large needle aspiration biopsy histology for preoperative selection of Hürthle cell thyroid nodules

AIMS

To assess whether the large needle aspiration biopsy (LNAB) histological distinction between pure microfollicular nodules and mixed micro-macrofollicular nodules can assist preoperative selection of a Hürthle cell nodule (HCN) discovered by fine needle aspiration cytology (FNAC).

METHODS AND RESULTS

In 24 HCN identified by preoperative FNAC, preoperative LNAB histology was compared with postoperative pathology. FNAC demonstrated seven benign HCN (negative), eight HCN with atypia (positive); seven suspected cancers with HC (positive); and two cancers with Hürthle cells (positive). LNAB showed mixed micro-macrofollicular hyperplastic features in 12 nodules (negative) and a microfollicular structure in 12 nodules (positive), two of which included findings of papillary cancer. Postoperative findings were benign (negative) in 16 patients and malignant (positive) in eight patients. The sensitivity and specificity for FNAC were 87.5% [seven of eight, 95% confidence interval (CI): 47.3-99.7%) and 37.5% (six of 16, 95% CI: 15.2-64.6%], respectively, and for LNAB were 87.5% (seven of eight, 95% CI: 47.3-99.7%) and 68.8% (11 of 16, 95% CI: 41.3-89.0%), respectively. FNAC results were significantly different from postoperative results (McNemar's test, exact two-sided P=0.012), while LNAB results were not (McNemar's test, exact two-sided P=0.219).

CONCLUSIONS

These data suggest that LNAB histology is more accurate than FNAC cytology for the preoperative selection of HCN.

Update on the molecular signature of differentiated thyroid cancer: clinical implications and potential opportunities

With the development and maturation of new technologies, there has been a steady incorporation of powerful new tools into the evaluation and management of thyroid nodules and thyroid cancer. An increasing number of reports on oncogene testing and molecular screening in fine-needle aspiration biopsy samples have been published. However, there remains a paucity of data and consensus on combining both conventional and molecular technologies to determine the diagnosis and/or prognosis of disease. All patients with differentiated thyroid cancer stand to benefit from the identification and incorporation of reliable molecular markers into clinical practice. Identification of reliable markers would allow for stratification of treatment, affording the medical and surgical teams an ability to individually tailor evaluation and treatment, applying aggressive therapy and monitoring only when clinically warranted. For the majority of patients with thyroid cancer, the incorporation of a validated, multifaceted molecular profiling system may not improve survival; however, there is great opportunity for these efforts to decrease the morbidity associated with our current approach.